Improvement in casting tuyeres



UNITED STATES PATENT OFFICE, I

WILLIAM M. JOHNSTON, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO HIMSELF AND DAVID I. ESTEP, OF SAME PLACE.

'IMPROVEM ENT IN CASTING TUYERES.

Specification forming part of Letters Patent No. 88,788, dated April 13, 1869.

To all whom t may concern Be it known that I, WiLLrAM M. JOHNSTON, of the city of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Manufacture of Tuyeres; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawing, making a part of this specification, in which- Figure l is a side elevation of the pattern by which is made the mold for the out-er face of the outer shell of the tuyere. Fig. 2 is a perspective view of the core-box in which is molded the sand core for the inside of the tuyere-shell. Fig. 3 is a longitudinal section of a core-box in which is molded the core for the tubular air-passages through the tuyere.

Fig. 4 is a perspective view of the nail-which I use as a support or "anchor7 for the core made in the core-box, shown in Fig. 2 5 and Fig. 5 is a vertical section of the tuyere-mold and cores when ready for the casting of the tuyere.

Like letters of reference indicate like parts in each.

The nature of my invention consists in cast-- ing a shell-tuyere at a single casting, with two or more pipes or air-passages through the tuyere for conducting the air from the bellows or fan to the fire on the forge.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and mode of operation, with particular reference to the making lof a tuyere having three separate pipes or air-passages leading from end to end, by which to admit the air from the bellows or fan to the rire on the forge at as many dierent points.

a is the pattern, the body of which is of the shape and size of the outside of the tuyere to be made. On the face of its smaller end are three molding prints or projections, a a a', arranged in the order of the desire d air-passages in the tuyere. On the sides ofthe body a of the pattern are two or more (two being the preferable number) projections, a, which extend out from the body a a distance somewhat greater than the thickness to be given to the outer shell of the tuyere to be made.

With such a pattern a sand-mold, b, is made in a ask, b', the projections a forming prints made. This is mortised at three points, more or less, according to the number of pipes desired in the tuyere, so as to receive patternblocks e. The arrangement of these patternblocks c relative to each other and to the axial line of the core to be made is the same as that of the prints in the mold b as formed by the projections a. These pattern-blocks e are steadied in place at their upper ends by an annular brace, e', extending from one to another, and fastened to all, but in such way as to be easily removed.

A' small hole is made in the bottom-plate (l, but large enough for a mold for a vent-hole in the tuyere-shell.

The sides of the core-boxf (indicated, some by full and some by dotted lines, Fig. 2) are then placed on the bed-plate d, and secured thereto and to each other by dowels 'or other equivalent device. The inner face of the box thus made corresponds in size vand shape to the size and shape of the inside of the outer shell of the tuyere.

In the sides j' small holes s are made, equal in number to the projections a, and similarly arranged. The lines of division of the sides f should pass through the holes s, so as to permit the removal of the sides f from the core without injury to the lugs or supports which are to be formed in such holes s. A core, g, is then made in such core-box.

The sand is filled into the hole in the bottoni plate d, by which is formed on the end ot' the core g a projection, d', equal in length to the thickness of the tuyere-shell. This projection d( forms the hole in lower or large end of the tuyere, (in the upper end, as east,) through which hole, while the casting is being done, the gases generated in the inside oi' the tuyere-shell make their escape, and by which, when the tuyere is in use, the water contained in the tuyere may be drawn oii, to

prevent injury by frost or from other causes.

The holes s s in the core-box f are also filled with sand, to form the lugs or supports c.

The sides f of the core-box are then removed, the ring e taken off, and the core g is lifted oft' the bed-plate d and pattern-blocks e; or, what is better, the pattern-blocks e are removed through the bed-piece d.

The core g is then inverted and carefully let down into the cavity previously made in the sandunold b, the supports c resting in the bottom of the recesses c', and such other support as the cord g may need is given to it by one or more bevel or grooved-necked nails, i, which are embeddedA in the sand-mold I) at the proper points, with their heads projecting out a distance equal to the thickness of the outer tuyere-shell.

In this way the core y is so supported in the cavity of the sand-mold b that a space, m, is left all around it for casting the sides of the tuyere-shell. At the same time the core g is shorter than the cavity of the sand-mold b, so that a space, n, is left above and below for casting the ends of the shell of the tuyere.

Somuch of the recesses c as is not occupied by the ends of the supports 0 is filled up with sand, as indicated in Fig. 5, the face of such llin g up being made even with the face of the sand-mold b adjacent thereto.

The apertures made in the core g by the pattern-blocks e are for the inner shell-that is to say, for molds in which to cast the tuyerepipes which conduct the air from the fan or bellows to the fire.

In making a core, h, for the inside of such pipes, I use a core-box, h', the bottom and sides of which are shown in Fig. 3. In the cavity h" of this core-box h, I make cores h, equal in number to the apertures in the core g, as made by the pattern-blocks c. I also make them somewhat smaller in cross-section than the apertures in the core g, as well as longer, and also with their lower ends, x, of the right size to t neatly into the prints made in the bottom of the mold b, as shown in Fig. 5, so that they may stand firmly in such prints, and a space, 0, be left all around, between each of them and the core g, in which to cast the tuyere-pipe, such spaces .o connecting at both ends with the spaces n for forming the ends of the tuyere-shell. The upper part,

b", of the mold is then placed in position and properly secured, and, a gate having been made, the complete mold is ready for the casting, which is done in the usual way.

In a mold ofpthis construction the tuyere maybe cast complete at a single casting. The spaces o, in which are cast the tuyere-pipes or inner shell, connect at each end with the the spaces n, in which are cast the ends of Athe shell, and these, all around the edges of the ends, open into the spaces m, in which the outer shell or sides are cast. The pipe-cores h are centered in the prints made in the bottom of the mold b, and, fitting closely therein, are held in the proper position. The projection d makes a hole in the end of the tuyereshell, for the uses already named. rlhe lugs c give holes in the sides of the tuyere, through which,`by supply and disch arge pipes attached thereto, water is admitted into and conducted out of the tuyere from and to any suitable tank or reservoir. As the casting is all done at once there can be no joints where a leak is liable to occur, and the pipes and sides of the tuyere being of the same, or nearly the same, length, the danger arising from other than a uniform shrinkage is wholly obviated. The gases generated or given off in the inside of the shell pass off, without doing the least injury, through the sand of the projection d and ot' the lugs c. The sand of the core gis removed, ofcourse, through the holes in the shell made bythe projection d and lugs c.

As already intimated, I do not limit myself to the particular form of tuyere shown, but apply my invention to the manufacture of pipe-tuyeres of two or more pipes. Hence What I claim as my invention, and desire to secure by Letters Patent, isl A cast-metal shell-tuyere having two or more pipes or air-passages through it from end to end, when such pipes or air-passages and the tuyere-shell are cast at a single casting, substantially as described.

In testimony whereof l, the said XVILLIAM M. JOHNSTON, have hereunto set my hand.

WM. M. JOHNSTON.

Vitnesses:

ELL TORRANCE, G. H. CHRIsTY. 

